Wild Tuna History
There are four distinct species of tuna which are commonly canned by packers, plus Tongol Tuna. Of the Five species of tuna only the Albacore may be labled as “White Meat”. The other species being slightly deeper in color when canned and Tongol, being small fish, tends to be almost white in color and tender, a little less dry than Albacore. Some prefer Tongol over all species when canned.
Little is knowns of trhe life history of the Tuna. They are “Scombroid” fish of the Mackerel family, far ranging, pelagic fishes of the open ocean. Although they are usually caught in the vicinity of some land, their presence close to the shore appears to be merely a phase of weide migration.
Alaska experienced a run of Albacore in 1948, extending the known range of this tuna far to the North. Where the tuna spawns and when and at what age, man is only beginning to learn. We know there are tuna in almost all the warmer seas of the world, but whether the mid-Pacific tuna is the same population as tehat fished along the Pacific Coast of the Americas is an unanswered riddle.
Highest prized and highest priced of the tunas is the Albacore, known to the scientist as Thunnus alalunga. This tuna is an unpredictable fellow.
In California he provided the major portion of the tuna pack from the beginning of the industry to the early “Twenties”. Then, after a record year in 1925, the species utterly disappeared, and was not again a commercial factor in the California fishery until 1942. In Pacific Northwest waters, on the other hand, the fish were never taken commercially until about 1937, and the first sizable pack of Albacore was put up in Oregon and Washington in 1938.
In California waters, on the other hand, the run of Albacore built-up with the passing of the 40’s and in 1948 and 1949 reached the greatest volume ever known.
The Albacore is the living embodiment of the stream-lined form, with the pointed head of a machine-gun bullet and the tapering tail of a jet plane.
The pectoral fins-those just behind the gill openings-are long and saber-shaped, actually being half the length of the entire body, and are the outstanding single characteristic of this tuna. The fisherman sometimes calls the Albacore “Longfin”.
Proof of the speed of these fish, and the natural provision for it, is the fact that these long saber-shaped fins when at rest actually lie in depressed grooves in the body of the fish. The dorsal fins along the back, which can be folded down into a groove entirely out of sight, reduce water resistance to the utter minimum.
Three physical characteristics distinguish the Albacore from the other tunas.
- The color of the flesh when prepared by canning is much lighter. Despite the fact that the Albacore is called White Meat Tuna, it is not white in the sense that the flesh of cod or halibut is white, but rather as the breast of chicken or turkey is “white”.
- Texture of the flesh of the Albacore is firmer that that of the other species, permitting a larger percentage to be canned as “solid pack.”
- “Recovery” is greater. This means that a larger number of cases can be canned from a ton of Albacore of equal size than it is possible to produce from a ton of any of the other species.
Commercial Albacore range in size from 9 to 30 lbs., but the average of those taken along the Pacific Coast is not over 15 lbs. The fish caught from Mexico north to Alaska are regarded by the scientists as immature, in that they have never spawned. Fish taken in the vicinity of the Hawaiian Islands, and west from there, generally are larger than the eastern Pacific average, and show evidence of having reached sexual maturity.
This tuna is by all odds the most important factor in the tuna pack, accounting for more than half of the entire American catch.
Virtually the entire production is taken from waters off Central and South America, only a handful of Yellowfin coming from California waters.
Yellowfin tuna range in size to above 200 pounds, although canners prefer not to pack specimens of more than 150 pounds in weight. The fish are taken throughout the year along the tropical and sub-tropical coast, generally moving northward during the summer months, and south again in the cooler part of the year above the Equator.\This tuna is taken in the southwestern Pacific, but the primary concentration known is that along the coast of North and South America. Scientists are beginning to find evidence that there is some spawning of Yellowfin in the vicinity of Costa Rica, but almost nothing is known of the life history of the species.
The flesh of the Yellowfin tuna is characteristic of the Light Meat grade of canned tuna. It is relatively soft in texture and full in flavor.
Scientific name of the Yellowfin is Thunnus albacares.
This is the smallest of the tunas, but second to the Yellowfin in importance as a component of the canned pack.
A little fish, ranging up to about 25 inches in length, the skipjack is readily distinguished by a number of dark horizontal stripes on the silvery surface of the lower part of the body. This marking leads to the name Striped Tuna, which is sometimes given to the species, although its use seems to be declining in favor of the term Skipjack.
Like the Yellowfin, the Skipjack tuna is caught almost exclusively in the waters off the coast of Mexico, Central and South America; the catch from California waters proper being insignificant.
Due to the small size of the Skipjack, recovery in cases canned per ton of fish is relatively small. The color of the flesh is slightly darker than Yellowfin, although this difference is so fine as to be noted only with difficulty.
Texture of the flesh is soft, and Skipjack must be handled with special care aboard the fishing vessel. The Skipjack which constitutes so important a part of the American tuna supply is known scientifically as Katsuwonus pelamis. There is another closely related species called the Oceanic Skipjack.
These two species make up the most important tonnage of the tunas taken in the western and mid-Pacific.
This is the “Tunny” of the ancient Romans, the tuna of classical antiquity, found in warm seas throughout the entire world, but never in great concentrations supporting major fisheries. Scientific name is Thunnus thynnus.
The Bluefin on the Pacific Coast is taken usually during the early summer, and along a relatively short section of the coastline from the latitude of Los Angeles south down the coast of Mexico. About one-third of the total Bluefin deliveries of California are taken from the ocean off that state, with two-thirds coming from the sea off the Mexican peninsula of Lower California.
Bluefin is the tuna of greatest interest to the sportsman, and is the species which supports the sport tuna fishery of the Atlantic Coast, and which provides a commercial fishery of growing importance in the Maritime Provinces of Canada, as well as along the coast of Maine.
Tongol is the best tuna for canning purposes due to its sustainability. It is a very seasonal fish caught mostly by small vessels in the waters along the Malay and Burmese coast. Also around the Indonesian archipelago there are local catches.
Product characteristics: The meat is quite tender and has an almost white color. It has a taste similar to albacore. It is often appreciated more by people than the somewhat drier albacore meat.
The seasonality of tongol tuna is determined by the weather. When the monsoon season comes there are no fish, if there were, the conditions prevent the small boats from catching enough product to send to the canning factory.
Future Supply: There is limited data available on the volume of the catch, and the status of the current stock. One reason is that tongol is mainly caught by small local vessels, which makes monitoring difficult. The general feeling is that tongol is catches could increase slightly and still maintain a sustainable level. Availabilty tends to be very seasonal, and restricted to mainly Indonesia and Thailand.
THE “TUNA-LIKE FISHES”
Official statistics often list “Tuna and Tuna-Like Fishes:. This latter characterization refers to two species which resemble tuna somewhat, and which are canned in identical manner, but which may not be labeled as tuna.
This the fish most commonly referred to under the “tuna-like” designation in the statistics. It is a close relative of the tunas, and somewhat resembles the Skipjack in appearance. The flesh is somewhat soft in texture.
Substantial quantities of bonito are canned, and it is an important factor in imports, particularly from the west coast of South America. In the western Pacific this species is said to be abundant.
This “tuna-like” fish belongs to a totally different family from the true tunas, and resembles tuna much more closely as a canned product than it does either in appearance or scientifically.
YIELD OF CANNED FISH PRODUCTS
Numbers of individual fish required to produce a case of the several products may vary widely between seasons and districts. For example, it is quite possible to can a full case of Chinook salmon-four dozen 1-lb. cans or eight dozen halves-from a single salmon. On the other hand, as many as five fish may be required.
Red salmon run much more uniform in size, requiring from 12 to 13 per case; and Silver salmon are usually counted 9 or 10 to the case, with Chums about the same. Although Pink salmon are said to average 17 to the case, not infrequently as many as 24 may be required.
Under the California law, canners were required to pack 13.5 cases for each ton of fish used in canning. The average is somewhat about this figure, as fish in good condition will yield about 20 cases per ton.
An average of four dozen Pacific crabs are required to pack a case of canned crabmeat.
HOW AND WHERE TUNA IS CAUGHT
American tuna fishermen take the fish by three distinct methods:
- Hook-and-line in connection with live bait;
- Purse seining;
- Trolling with specialized lures called “jigs.”
In the Orient a number of additional methods of tuna fishing are employed, but to date these have not been adapted effectively to the fish encountered and the type of operations engaged in by American tuna fishermen.
Fishing for tuna with live bait is the backbone of the business, and takes by far the larger part of the catch. This method may be employed by craft of any size from perhaps 50 feet up, but in general it is practiced by vessels of the type which has come to be known throughout the world as the “tuna clipper.”
Stripped to its essentials, the definition of a tuna clipper might be phrased thus:
“A vessel equipped to carry small fish alive for use as bait; and capable of being trimmed in such a way as to bring its stern rail as low as possible in the water.”
Outwardly, the tuna clipper is readily recognized by the big bait tank carried on the stern. Sea water is circulated through this tank and the small fish-sardines and anchovies-are kept alive in the tank until they are used in fishing.
Actual fishing from a clipper is done by men standing on iron racks hung outside the rail at the stern of the vessel, which is trimmed down until the men are standing almost level with the water. This is necessary in order to enable them to swing the big tuna aboard with their poles.
When a school of tuna is located, which may be accomplished by observing them feeding, by catching means, a few of the live fish from the bait tank are thrown into the water alongside the clipper. This induces a feeding frenzy in the school.
The fishermen on the racks are equipped with heavy bamboo poles, each with a short line carrying a “Squid”, a sort of glorified trout fly with a barbless hook.
In the excitement of feeding, the tuna strike at these hooks and are swung aboard the vessel.
When the school is made up of tuna too large for one man to handle, two, three, or even four poles may be bridled together to a single hook.
Live bait is used to keep the school close to the vessel and in a feeding excitement. Without such bait, there is no fishing.
TUNA PURSE SEINING
Netting tuna by means of a purse seine follows the essentials of the method described in connection with salmon fishing. A school of tuna is surrounded by a big net, the bottom of which is “pursed” shut by means of a cable running through rings attached to the lower edge of the net. Thus surrounded, the fish are unable to escape from the net, and finally are crowded together and aseiner.
TUNA JIG FISHING
This method of fishing is customarily practiced only by rather small vessels-those running from 30 to 60 feet in length-although big clippers use it in scouting for fish.
It is an adaptation of trolling, with the artificial lures, known as “jigs,” fished close to the surface. The method is of much greater importance in the Albacore fishery than it is for the other tunas.
The lures are made of various substances and in several types, of bone and plastic, metal, feathers and rubber.
DIFFERENT SPECIES, DIFFERENT METHODS
Bait fishing is the dominant factor in the production of Yellowfin and Sikipjack tuna, although these species are also taken by means of purse seining.
Bait fishing and jigging are the methods employed in catching Albacore tuna. These fish can be taken by purse seining, but to date that method has not proven economically successful for Albacore.
TUNA FISHING IS BIG BUSINESS
The operator of a tuna clipper or tuna seiner is really a businessman. A good-sized clipper will run from 120 to 150 feet in length, and may carry as much as 2,000 horsepower in her diesel engines –of which there will be not less than three.
Beside the main engine driving the clipper there are at least two diesel auxiliaries running up to 250 horsepower each to provide power for her refrigeration machinery and pumps.
A clipper of this sort may cost over $700,000. Some have run well above this figure.
Most tuna purse seiners are not so large as the clippers, but they are almost as expensive proportionately, while the nets they use are very large and costly.
Question is often raised as to how it is possible for tuna fishing vessels to make long trips, returning to port or central boat, with full cargoes of several hundred tons of prime tuna after having been at sea for three or four months. How is it possible to keep fish for several weeks, or even months, without deterioration?
Until the tuna industry worked out the answer to this question it could not attain the stature and volume of production which has marked it in recent years.
Until it was learned how to keep fish in perfect condition abord the fishing vessel for weeks it was not possible to extend tuna operations to the point where more cases a year could be produced.
The old methods of air-chilling were tried early, but it did not prove possible to chill and keep tuna by this means in the volume and at the rate in which the fish may be received when fishing is flush.
Gradually developed over a period of years, a brine-chilling method was worked-out which proved entirely satisfactory; and this opened for the tuna industry the way to greatness.
BRINE CHILLING TUNA
Very briefly, the process of brine-freezing is this:
The hold of a tuna clipper is filled with “cargo wells,” which are in fact compartments with hatches opening on deck. These wells are lined with refrigeration piping, and are fitted so that brine may be circulated through and through the wells.
Outward-bound to the fishing grounds, the clipper fills at least a portion of the cargo wells with seawater, to which additional salt is added to permit the temperature to be lowered below the normal freezing point of ocean water. The refrigeration machinery is operated, and the brine in the wells circulated over the coils lining the wells until its temperature is well below freezing.
As soon as the fish are caught they are slipped into one of the brine wells. Circulation of the brine over the frost coils is continued until the tuna are thoroughly frozen by the low-temperature brine. Once the fish are frozen through-and-through, the chilled brine is pumped into another tank and the frost coils take up the task of “holding” the fish frozen in the dry state.
HOW TUNA IS CANNED
Upon delivery at the cannery, sometimes a floating cannery on a huge central boat, the tuna are thawed (if they have been frozen aboard the fishing vessel) and are then dressed.
Dressed tuna are placed in racks in wheeled trucks, sorted somewhat according to size. Filled racks are rolled into pre-cookers, where the fish are subjected to a steam cook for a period depending upon size of the fish
Upon completion of the pre-cook the racks are withdrawn and are wheeled into a well-ventilated area for cooling. Time required to cool depends upon temperature, humidity and size of fish. It will average about 12 hours.
CANNED TUNA PROCESS COOK
After putting the tuna in the open can, closing the tin follows either exhaust box or vacuum seaming; and the can is then given the process cook in a retort, time and temperature of this cook being shown in a table elsewhere in this booklet.
GRADES OF CANNED TUNA
“White Meat” may be used as a label designation only on canned Albacore.
Other species of tuna such as Yellowfin, Skipjack and Bluefin may be labeled “Light Meat Tuna,” or simply “Tuna”. Tongol Tuna is labeled Tongol Tuna.
Under each of these general classifications based upon color of the canned flesh it is customary to pack several grades, based essentially upon the size of the pieces of fish.
The industry’s trade practice rules establish standards as follows:
Fancy-Packed with choice cuts from fish of not over 60 pounds weight, with only large pieces in the can, with one or two small pieces of solid meat added, if necessary, to provide full weight, but with no flakes, grated or shredded tuna added at time of packing. No skin, bones or dark meat may be included.
Standard-Packed with at least 75% of the can contents consisting of large pieces. The balance may be flakes. Size of fish is not prescribed. No skin, bones nor dark meat may be included.
Grated, Shredded or Flakes-Packed of small pieces of tuna from which bones, skin and extraneous tissue have been excluded.
Tonno-This is a type of canned tuna put up as a specialty item for the Italian-American trade. It consists of solid-pack Skipjack-sometimes Bluefin-packed with twice the usual amount of salt, and in olive oil instead of the customary salad oil.
Tonno is usually packed in quarter-pound tins of the “Kanopen” type.
Most tuna of the Fancy and Standard grades is packed in the cans by hand. However, in 1949 tuna filling machines of at least two types were introduced by the industry, and in that year for the first time a considerable quantity of machine-packed tuna was marketed.
Shredded or Flake tuna customarily is machine-filled by one of several machines adapted from vegetable canning. These consist of cylindrical pockets which are filled with the small pieces of tuna, and the contents then being pressed into the can by a piston or plunger.
OIL IN CANNED TUNA
Some tuna is canned with the addition of salt and oil, with the exception of a “water” pack discussed later. The oil used is customarily one of the bland “salad oils”, commonly cottonseed, corn or soya oil. Olive oil is occasionally used on specialty packs.
The oil has two functions in canned tuna.
First, it replaces in the structure of the tuna the natural oil which has been removed by pre-treatment because of its rather strong, fishy flavor.
Second, to moisten, lubricate and insulate the tuna surfaces in contact with the can-and thus to prevent “scorching” during the process cooking. If oil or water is not added to tuna before processing, and if it does not have opportunity to moisten all surfaces of the fish, there is danger that some of the fish will stick to the metal of the can and suffer over-cooking, which produces the undesirable flavor known to examiners as “scorching”.
The oil added to canned tuna is salad oil of the highest quality. Dieticians advocate using it in recipes in which the tuna is employed because of its intrinsic food value and because it has taken up fine flavors from the tuna.
“Water pack” CANNED FISH
Production of “water pack” canned fish was pioneered late in 1949 by one tuna packer, who announced a special pack of low-fat, high protein, low-cholesterol, low-salt tuna for use in special diets designed for weight reduction, protection against certain heart troubles, and high blood pressure.
In this pack the tuna is canned in distilled water without added oil or salt.
Fat content of the dietetic pack is reported as 0.75%. Calories are 122 per 100 grams. Protein is given as 28.3%.
U.S. PACK OF CANNED TUNA
The United States is at once the world’s great tuna market and world’s great tuna-producer. As a matter of fact, this country consumes a much greater proportion of the world’s canned tuna pack than it produces.
This condition has prevailed since the early days of the industry. Since the early Twenties, the United States has imported tuna. In that time it came almost exclusively in the form of fish frozen in Japan and shipped to this country for canning. The principal species imported was Albacore.
During the late Twenties the tuna canned from this imported Albacore constituted practically the only stock of White Meat Tuna available in the United States.
In the early Thirties the Japanese began to develop a tuna-canning industry of their own, and the trend of shipments to this country started to swing from frozen fish for canning to the already canned.
Japanese shipments to the United States peaked in 1933 with imports of 600,000 cases, 44.2% of total amount of tuna canned in this country in that year.
This fish was sold at prices below those of the American producers, and brought the domestic business to the brink of disaster. The percentage of imports to the American production declined from the 1933 peak, but remained very considerable until the outbreak of the war in Europe in 1939.
Imports of canned tuna during this period, domestic production, and the percentage of imports to domestic production, are shown in this table:
During the second world war, and particularly since, there has been a gradual increase in the imports of tuna to the United States-both frozen for canning, and already canned.
A substantial industry has developed in South America, notably in Peru, and there are signs of growth in Ecuador as well. Japan has resumed canning tuna, and moderate imports of canned fish have been received from there; while shipment of frozen Albacore from Japan was resumed in 1948 and has been growing since.
Africa has been coming to the fore as a canner of tuna and material shipments from Algiers, Morocco and Angola have been reaching the United States market.
Statistically, there has also been a sharp increase of imported frozen tuna in Central America. This fish largely was caught by American vessels and landed in Central America for storage in shore freezing plants and subsequent shipment to the United States aboard intercoastal carriers.
“CHUNK STYLE” TUNA PACK
Introduced on a considerable scale in 1949, this new-type of tuna pack attained instant consumer acceptance. The result was that a substantial percentage of the Light Meat tuna pack was put-up in this style in 1949 and maintained growth since.
The “chunk style” pack is prepared by cutting the loins of tuna, small fish customarily being used, into small chunks or “bite-size” pieces. These are filled into the cans without crushing. The product reaching the consumer is already cut into small pieces for use, but is not so mascerated as flakes, grated or shredded tuna.